Before you start

California residence
Income information for subsidy or Medi-Cal eligibility
An SSN or ITIN for the marketplace application
A qualifying life event, if enrolling outside the annual open-enrolment window

Step-by-step

1
Enrol in your employer's plan within the new-hire window
Typically 30 days from your start date, and missing it can mean waiting for the next open enrolment. Compare the deductible and out-of-pocket maximum, not just the premium — and if you work in Orange County or Los Angeles County, check that the network actually covers providers where you live.
Via employerWho: YouFirst 30 days of employment
2
Check Medi-Cal eligibility first — and know you get a choice here
California expanded Medi-Cal well beyond the federal minimum, and in 2024 extended full-scope coverage to income-eligible adults regardless of immigration status. The 2025 state budget changed the terms for new adult enrolment and added premiums from later years, so confirm the current position with the Department of Health Care Services. In Riverside County, Medi-Cal runs on the Two-Plan model — the Inland Empire Health Plan or Molina Healthcare — so the choice of plan and of primary care provider is genuinely yours. Medi-Cal enrols year-round.
OnlineWho: You
3
Without an employer plan, use Covered California — not HealthCare.gov
California runs a state-based exchange with its own enrolment calendar, which has historically extended past the federal deadline, and its own state subsidies layered on the federal ones. Going to the federal site sends you back.
OnlineWho: You
4
Understand the state individual mandate
California kept an individual mandate after the federal penalty went to zero. Going without minimum essential coverage for a substantial part of the year triggers a penalty on your California return unless you qualify for an exemption. It is administered by the Franchise Tax Board, not by the marketplace, and people who assume the federal repeal ended it get caught at filing.
OnlineWho: You
5
Check which hospital system your plan actually reaches
Riverside University Health System is the county's public hospital and clinic network, with Kaiser Permanente, Riverside Community Hospital and Loma Linda University Health nearby. Plan networks are drawn along those lines, and Kaiser in particular is both insurer and provider — a closed system you get care inside or pay out of pocket. Check before enrolling; switching mid-year needs a qualifying life event.
OnlineWho: You
6
Register with a primary care physician in month one — and expect a wait
The Inland Empire has one of the lower physician-to-population ratios in California, so establishing with a GP takes longer here than on the coast. Do it while you are well; an established relationship is what gets you referrals and urgent slots later.
In personWho: YouMonth 1
7
Treat air quality as a managed health variable
Check South Coast AQMD's daily forecast the way you would check pollen elsewhere. Ozone peaks on hot afternoons in summer and autumn, particulate spikes during wildfire smoke events and around freight corridors. A decent indoor air filter, and moving exercise to the morning in summer, are ordinary local practice. If anyone in the household has asthma, raise this with a GP in the first month rather than the first bad week.
In personWho: You
8
Plan for Santa Ana wind, fire and smoke season
Autumn offshore winds drop humidity into single figures and drive the region's worst fire weather in the surrounding hills and canyons. Know your address's fire hazard severity zone on the state fire marshal's map, keep N95 masks, and sign up for the county's emergency alert system. Smoke from fires elsewhere in the state also settles into this basin.
OnlineWho: You

Documents you’ll need

Proof of California residence
Income documentation for subsidies or Medi-Cal
SSN or ITIN
Immigration documents for marketplace eligibility categories
Evidence of losing prior coverage, if using a special enrolment period

Things most newcomers don’t know

The air here is the health fact that no rent comparison shows you.

The South Coast Air Basin is classified Extreme nonattainment for ozone — the most severe category the Clean Air Act has — and the sea breeze pushes pollution generated across the Los Angeles basin inland, where it accumulates against the mountains. Riverside is at the receiving end of that, with warehouse and freight diesel added locally. It is manageable and millions of people manage it; it is not something to discover after signing a lease with an asthmatic child.

Source: US EPA Green Book / South Coast AQMD

The rules on what can be built next to a house changed on 1 January 2026.

AB 98 imposed statewide standards on new and expanded logistics developments from that date — 300-foot setbacks from loading bays in industrial areas and 500 feet in non-industrial ones where a sensitive receptor is within 900 feet, mandatory design elements above 250,000 square feet, and an approved truck routing plan before occupancy. The Inland Empire is the region that law was written about. It does nothing for the warehouses already there, which is precisely why the seasonal air quality pattern at a specific address is worth checking rather than assuming.

Source: California Legislature — AB 98 (2024)

Riverside County's Medi-Cal is a choice, unlike Orange County's.

Riverside runs the Two-Plan model — the Inland Empire Health Plan, a public plan created by Riverside and San Bernardino counties, or Molina Healthcare. In Orange County an eligible resident is simply enrolled with CalOptima. Having a choice means the provider network question is real: ask which plan your preferred GP and paediatrician take before you pick, because switching afterwards is harder than choosing well.

Source: California Department of Health Care Services / Inland Empire Health Plan

California still has an individual mandate, and it is enforced through the state tax return.

The federal penalty went to zero in 2019 and most people assume mandates ended everywhere. California, Massachusetts, New Jersey, Rhode Island, Vermont and DC kept theirs. In California it is assessed by the Franchise Tax Board when you file, and a newcomer who arrives mid-year uninsured can owe it without ever having heard of it.

Source: California Franchise Tax Board

Medi-Cal's rules on immigration status have moved twice in three years.

California extended full-scope Medi-Cal to income-eligible adults regardless of immigration status in 2024, and the 2025 state budget changed the terms for new adult enrolment and added premiums from later years. This is one of the fastest-moving eligibility questions in the country. Anything written more than a year ago is likely wrong in one direction or the other — check with the Department of Health Care Services directly.

Source: California Department of Health Care Services

Common mistakes to avoid

Going to HealthCare.gov instead of Covered California and losing time.
Assuming no coverage means no penalty, when California still levies one.
Choosing a Medi-Cal plan without checking which one your preferred GP takes.
Missing the 30-day new-hire enrolment window at a new employer.
Taking a house near a freight corridor without checking the seasonal air quality pattern.
Enrolling in Kaiser without realising it is a closed system.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.